1 files changed, 184 insertions, 0 deletions
diff --git a/internal/store/header_test.go b/internal/store/header_test.go
new file mode 100644
index 00000000..51a6939a
--- /dev/null
+++ b/internal/store/header_test.go
@@ -0,0 +1,184 @@
+package store
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"io/fs"
+	"os"
+	"reflect"
+	"syscall"
+	"testing"
+	"time"
+
+	"hakurei.app/hst"
+)
+
+func TestEntryHeader(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		name string
+		data [entryHeaderSize]byte
+		et   hst.Enablement
+		err  error
+	}{
+		{"complement mismatch", [entryHeaderSize]byte{0x00, 0xff, 0xca, 0xfe, 0x00, 0x00,
+			0x0a, 0xf6}, 0,
+			errors.New("header enablement value is inconsistent")},
+		{"unexpected revision", [entryHeaderSize]byte{0x00, 0xff, 0xca, 0xfe, 0xff, 0xff}, 0,
+			errors.New("unexpected revision ffff")},
+		{"invalid header", [entryHeaderSize]byte{0x00, 0xfe, 0xca, 0xfe}, 0,
+			errors.New("invalid header 00fecafe")},
+
+		{"success high", [entryHeaderSize]byte{0x00, 0xff, 0xca, 0xfe, 0x00, 0x00,
+			0xff, 0x00}, 0xff, nil},
+		{"success", [entryHeaderSize]byte{0x00, 0xff, 0xca, 0xfe, 0x00, 0x00,
+			0x09, 0xf6}, hst.EWayland | hst.EPulse, nil},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			t.Run("encode", func(t *testing.T) {
+				if tc.err != nil {
+					return
+				}
+				t.Parallel()
+
+				if got := entryHeaderEncode(tc.et); *got != tc.data {
+					t.Errorf("entryHeaderEncode: %x, want %x", *got, tc.data)
+				}
+
+				t.Run("write", func(t *testing.T) {
+					var buf bytes.Buffer
+					if err := entryWriteHeader(&buf, tc.et); err != nil {
+						t.Fatalf("entryWriteHeader: error = %v", err)
+					}
+					if got := ([entryHeaderSize]byte)(buf.Bytes()); got != tc.data {
+						t.Errorf("entryWriteHeader: %x, want %x", got, tc.data)
+					}
+				})
+			})
+
+			t.Run("decode", func(t *testing.T) {
+				t.Parallel()
+
+				got, err := entryHeaderDecode(&tc.data)
+				if !reflect.DeepEqual(err, tc.err) {
+					t.Fatalf("entryHeaderDecode: error = %#v, want %#v", err, tc.err)
+				}
+				if err != nil {
+					return
+				}
+				if got != tc.et {
+					t.Errorf("entryHeaderDecode: et = %q, want %q", got, tc.et)
+				}
+
+				if got, err = entryReadHeader(bytes.NewReader(tc.data[:])); err != nil {
+					t.Fatalf("entryReadHeader: error = %#v", err)
+				} else if got != tc.et {
+					t.Errorf("entryReadHeader: et = %q, want %q", got, tc.et)
+				}
+			})
+		})
+	}
+}
+
+func TestEntrySizeError(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		name string
+		err  error
+		want string
+	}{
+		{"size only", &EntrySizeError{Size: 0xdeadbeef},
+			`state entry file is too short`},
+		{"full", &EntrySizeError{Name: "nonexistent", Size: 0xdeadbeef},
+			`state entry file "nonexistent" is too short`},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			if got := tc.err.Error(); got != tc.want {
+				t.Errorf("Error: %s, want %s", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestEntryCheckFile(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		name string
+		fi   os.FileInfo
+		err  error
+	}{
+		{"dir", &stubFi{name: "dir", isDir: true},
+			syscall.EISDIR},
+		{"short", stubFi{name: "short", size: 8},
+			&EntrySizeError{Name: "short", Size: 8}},
+		{"success", stubFi{size: 9}, nil},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			if err := entryCheckFile(tc.fi); !reflect.DeepEqual(err, tc.err) {
+				t.Errorf("entryCheckFile: error = %#v, want %#v", err, tc.err)
+			}
+		})
+	}
+}
+
+func TestEntryReadHeader(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		name string
+		newR func() io.Reader
+		err  error
+	}{
+		{"eof", func() io.Reader { return bytes.NewReader([]byte{}) }, io.EOF},
+		{"short", func() io.Reader { return bytes.NewReader([]byte{0}) }, &EntrySizeError{Size: 1}},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			if _, err := entryReadHeader(tc.newR()); !reflect.DeepEqual(err, tc.err) {
+				t.Errorf("entryReadHeader: error = %#v, want %#v", err, tc.err)
+			}
+		})
+	}
+}
+
+// stubFi partially implements [os.FileInfo] using hardcoded values.
+type stubFi struct {
+	name  string
+	size  int64
+	isDir bool
+}
+
+func (fi stubFi) Name() string {
+	if fi.name == "" {
+		panic("unreachable")
+	}
+	return fi.name
+}
+
+func (fi stubFi) Size() int64 {
+	if fi.size < 0 {
+		panic("unreachable")
+	}
+	return fi.size
+}
+
+func (fi stubFi) IsDir() bool { return fi.isDir }
+
+func (fi stubFi) Mode() fs.FileMode  { panic("unreachable") }
+func (fi stubFi) ModTime() time.Time { panic("unreachable") }
+func (fi stubFi) Sys() any           { panic("unreachable") }